Classified documents were found Tuesday at the Indiana home of former Vice President Mike Pence.

A lawyer for Pence found about a dozen documents marked as classified and turned them over to the FBI, CNN reported.

In response, the Justice Department and FBI have launched an investigation to determine how the documents ended up at Pence’s home.

The level of classification of the documents is not known at this time.

This follows the discovery of classified documents at President Joe Biden’s home and office dating to his time as vice president, as previously reported by The Dallas Express. In August, classified documents were found at former President Donald Trump’s Mar-a-Lago home.

This marks the third time in the past few months that a president or vice president has been discovered to have retained inappropriate possession of classified documents after leaving office, which sources suggested to CNN shows a pattern that highlights a systemic problem.

Classified documents are supposed to be handed over to the National Archives.

Pence had previously commented that there were no classified documents at his home, but his attorneys notified leaders in Congress as well as various committees of the discovery on Tuesday.

“I did not,” Pence replied to a question from ABC News regarding whether he had classified documents in his possession in November. “Well, there’d be no reason to have classified documents, particularly if they were in an unprotected area. But I will tell you that I believe there had to be many better ways to resolve that issue than executing a search warrant at the personal residence of a former president of the United States.”

The lawyer who discovered the documents also told the National Archives about the discovery.

“Vice President Pence was unaware of the existence of sensitive or classified documents at his personal residence,” Greg Jacob, who deals with Pence’s records related to his time in office, wrote in a letter to the National Archives. “Vice President Pence understands the high importance of protecting sensitive and classified information and stands ready and willing to cooperate fully with the National Archives and any appropriate inquiry.”

The documents, according to CNN, were taped up in boxes and not in a secure location. After their discovery, the documents were reportedly put into a safe at Pence’s home.

Texas Republican Michael McCaul, chairman of the House Foreign Affairs Committee, said that the retention of classified documents should not be happening.

“I don’t know what to tell you other than it’s not permissible, whether you’re a chairman of a committee or president of the United States or vice president. And I’ve been dealing in the classified world all my career; I don’t understand people taking these documents home. If you do that, you’re supposed to have a safe designated for storage and you have to have a proper briefcase to carry it in. I don’t know all the facts here,” McCaul said.

Trump spoke out in defense of Pence on his social media platform, Truth Social:

“Mike Pence is an innocent man. He never did anything knowingly dishonest in his life. Leave him alone!!!” he wrote.